JPS595955B2 - fire alarm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables a receiver to detect the removal of the main body of a plurality of fire detectors connected in parallel to a line leading to the receiver, and also detects the alarm when a subsequent fire detector fires after the removal. The present invention also relates to a fire alarm system that can receive alarm signals.

Generally, a fire alarm (hereinafter abbreviated as an alarm 6) is a system in which a plurality of fire detectors (hereinafter abbreviated as a detector) are connected to a line.

) are connected in parallel in sequence, and the receiver receives and detects the fire alarm signal from each sensor, and performs actions such as alarms.

As shown in Figure 1, the detector used in this alarm includes a socket 2 that is installed on the ceiling of a building and connected to the alarm line, and a main body 3 that has a smoke, heat, etc. detection section. A holding fitting 4 comprising an elastic piece 4b for holding the socket 2.
The fitting fitting 5 of the main body 3 is fitted and connected to the body 3 for installation.

However, since the main body 3 is detachably attached, it may be removed from the socket 2 by residents who find false alarms bothersome or by trespassers, which poses a disaster prevention problem.

Since a plurality of sensors are connected in parallel, there is a problem in that even if some of the sensor bodies are removed, the receiver cannot detect this.

Therefore, conventionally, as shown in FIG. An annunciator has been proposed in which a terminating circuit 8 consisting of a resistor 8a and the like is connected to the end of the line 7 so that the receiver 6 can detect the removal of the main body 3.

As shown in FIGS. 1 and 3, the contact mechanism 9 of the sensor consists of a holding fitting 4, an elastic piece 11 provided adjacent to the holding fitting 4, and a fitting fitting 5. When fitted into the socket 2, the fitting metal fitting 5 is in contact with the holding fitting 4 and the elastic piece 11, so that the line 7 is electrically connected and power is supplied to the detection unit 10.

Further, when the main body 3 is removed, the holding fitting 4 and the elastic piece 11 are insulated, the contact mechanism 9 becomes non-conductive, the line is cut off, and the removal of the main body 3 is detected.

However, the above-mentioned conventional alarm system has a practical problem in that if one of the connected sensors is removed, the line will be disconnected, making all subsequent sensors inoperable. It has drawbacks.

The present invention has been made in view of the above-mentioned drawbacks, and by temporarily or periodically cutting off the line when the main body of the sensor is removed, the main body of the sensor can be removed without interfering with the operation of other sensors. The purpose is to obtain a fire alarm that can detect removal.

That is, in the present invention, a plurality of sensors are sequentially connected in parallel to a line leading to a receiver, a termination circuit is provided at the end of the line to form a closed circuit, and one side of the line is connected to each sensor. In an alarm system in which each sensor is sequentially connected to other sensors via relay, each sensor is provided with a means for temporarily or periodically interrupting the relay of the line when the main body is removed, and the receiver is Means for detecting temporary or periodic interruption of the line is provided.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

Fig. 4 is a wiring diagram showing one embodiment of the alarm device of the present invention;
7 to 7 are side views and top views showing various aspects of the contact mechanism using this embodiment, and FIGS. 8 to 12 are side views showing various aspects of the opening/closing mechanism used in this embodiment. This figure and FIG. 16 are circuit diagrams showing a receiver used in this embodiment.

In FIG. 4, the alarm system of the present invention has a plurality of sensors 1 connected in parallel to a line 7 that forms a closed circuit with a receiver 6 and a termination circuit 8, and one of the lines 7 is sequentially connected to another sensor. The receiver 6 is provided with a contact mechanism 12 that is always in a conductive state and relay-connected to the main body, and an opening/closing mechanism 15 that temporarily brings the contact mechanism 12 into a non-conductive state when the main body is removed. It has been established.

The contact mechanism 12 includes a relay terminal 7a of each sensor 1,
? b, and is always in a conductive state regardless of the presence or absence of the main body 3, and the line 7 is successively relay-connected to other sensors 1.

This contact mechanism 12 may be constructed of the holding fitting 4 or the like, or may be provided separately.

The contact mechanism 12 shown in FIG. 5 is an example of the former, in which an elastic piece 11 made of a metal member is provided in the socket 2 so as to face and contact the sliding surface 4a of the holding fitting 4 with the fitting metal fitting 5. The tip 11a of the elastic piece 11 is brought into pressure contact with the sliding surface 4a by its elastic force, so that it is always in a conductive state.

What is shown in FIG. 2C is an example in which the elastic pieces 11 are deviated and brought into opposing contact.

The contact mechanism 12 shown in FIGS. 6 and 7 is an example of the latter, and separately from the holding fitting 4, etc., it has a pressure-sensitive switch such as a micro switch 13 or a reed switch 14, which is always in a conductive state, and a hole switch. A magnetically sensitive switch such as an element switch (not shown) is provided in the socket 2.

In this case, the holding metal fitting 4 and the fitting metal fitting 5 are connected to the contact mechanism 12.
It functions to hold the main body 3 and as an input/output terminal for the detection unit 100.

The opening/closing mechanism 15 is mainly provided in the sensor main body 3, and has the function of temporarily bringing the contact mechanism 12 into a non-conducting state when the main body 3 is removed, and temporarily interrupting the relay of the line 7.

The configuration of this opening/closing mechanism 15 differs depending on the aspect of the contact mechanism 12, and as shown by the symbol A in FIG. As shown by B, some terminals do not function as input/output terminals.

The opening/closing mechanism 15 shown in FIGS. 8A and B and FIG. 9 corresponds to the contact mechanism 12 consisting of the holding fitting 4 and the elastic piece 11 shown in FIG. It becomes a component and becomes an input/output terminal of the detection section 100.

That is, the opening/closing mechanism 15 shown in FIGS. 8A and 8B has a fitting fitting 5.
An insulating member 16 is attached to a part of the sliding contact portion 5a with the holding fitting 4 or the elastic piece 11, and when the fitting fitting 5 is removed from the holding fitting 4, the holding fitting 4 or the elastic piece 11 is attached to the insulating member. 1
6 to insulate the holding fitting 4 and the elastic piece 11.

The opening/closing mechanism 15 shown in FIG. 9 has an insulating member 16 protruding from the non-sliding portion of the surface of the elastic piece 11 facing the holding fitting 4, and when the main body is removed, the insulating member 16 is removed by the fitting fitting 5. is pressed to separate and insulate the holding fitting 4 and the elastic piece 11.

The opening/closing mechanism 15 shown in FIG. 10 corresponds to the contact mechanism 12 consisting of the holding fitting 4 and the elastic piece 11 as described above.
In particular, it is combined with the contact mechanism 12 shown in FIG. 5C.

The opening/closing mechanism 15 includes a protrusion 17 provided on the sensor body 3 adjacent to the fitting fitting 5.
Therefore, when removing the main body, the elastic piece 11 is pressed to separate and insulate it from the holding fitting 4.

This protrusion 17 has an elastic piece pressing portion 17a that does not prevent contact between the elastic piece 11 and the fitting fitting 5 during fitting, and prevents the main body 3 from interfering with the elastic piece 11 and the fitting fitting 5.
The elastic piece 11 is provided at a position where the elastic piece 11 can be pressed before it is removed from the socket 2, for example, at a position shown by reference numeral C in FIG.

The opening/closing mechanism 15 shown in FIG. 11 and FIG.
This corresponds to the contact mechanism 12 consisting of a pressure-sensitive switch or a magnetically-sensitive switch shown in FIGS.

That is, the opening/closing mechanism 15 shown in FIG. 11 consists of a protrusion 17 provided on the main body 3 facing the microswitch 13, and when the main body is removed, the protrusion 17 presses the pressure sensitive part 13a of the microswitch 13. Then, the microswitch 13 is brought into a non-conductive state.

Further, the contact mechanism 15 shown in FIG.
4 is provided on the main body 3, and when the main body is removed, the magnet 18 separates and insulates the magnetic tongues 14a+14b of the reed switch 14.

Both are provided in the socket 2 at a position where they come into contact with or approach the microswitch 13 or the reed switch 14 when the main body is removed, for example, at the position shown by reference numerals in FIG. 13.

FIG. 14 shows an example in which the contact mechanism 12 and opening/closing mechanism 15 are applied to a plug-in sensor.

In the figure, the contact mechanism 12 is made up of two elastic pieces 11 whose tips are in pressure contact with each other, and the opening/closing mechanism 15 is made up of an insertion piece 1.
9 and an insulating member 16 is attached to the tip thereof.

Note that it goes without saying that a pressure-sensitive switch or a magnetically-sensitive switch can be applied.

In each of the above embodiments, the direct contact mechanism 12 becomes non-conductive due to the action of the opening/closing mechanism 150, but conversely, as shown in FIG. However, it is also possible to configure a contact mechanism 12 that makes the line 7 non-conductive when the reed switch 14 becomes conductive.

That is, the embodiment shown in the figure includes a reed switch 14 which is always in a non-conducting state, a monostable multivibrator 20 with one end of the reed switch 14 connected to a trigger input terminal, and a coil 21a connected in series with the multivibrator 20. And the switching contact 21b is a relay terminal? It consists of a relay 21 connected between a and 7b.

In this embodiment, when the reed switch 14 becomes conductive due to the approach of the magnet 18 when the main body is removed, a trigger is applied to the monostable multi-pipe brake 20, a pulse of a constant width is output, and the relay 21 is energized. The opening/closing contact 21b is in a non-conducting state.

The receiver 6 has a fire alarm detection circuit 22, a line cutoff detection circuit 25, and a power supply 30, and supplies power to each sensor 1 through the line 1, and receives fire alarm signals and signals from each sensor 1. Detects body removal.

FIG. 16 is a circuit diagram showing a specific example thereof.

In the figure, the fire alarm detection circuit 22 consists of a coil 23a connected in series to the line 7, and a switching contact 23b connected in parallel to the line 7, and an alarm device 24 is connected in series with the switching contact 23b. ing.

The opening/closing contact 23b constitutes a make contact, and becomes conductive when the coil 23a is energized by a fire alarm signal consisting of a short circuit current, thereby activating the alarm device 24.

Further, the circuit break detection circuit 25 includes, for example, a relay consisting of a coil 26a connected in series to the line 7 and a switching contact 26b connected in parallel to the line 7, and a coil 27a connected in series with the switching contact 26b, which is also connected in parallel. It consists of a switching contact 27b connected to the line 7 and a switching contact 27c separately connected in parallel with the line 7, and an alarm device 29 is connected in series with the switching contact 27c.

The opening/closing contact 26b constitutes a break contact, and the opening/closing contact 26b constitutes a break contact.
7b and 27c constitute make contacts.

Therefore, the opening/closing contact 26b is non-conductive when current is flowing through the line 7, and becomes conductive when the relay of the line 7 is cut off by removing the main body and no current flows through the line 7, and the coil 27a is attached. to strengthen

As a result, the opening/closing contact 27c becomes conductive and the alarm device 29 is activated.

At the same time, the opening/closing contact 27b becomes conductive, and the energization of the coil 27a is self-maintained.

Therefore, temporary interruption of the line 7 by the contact mechanism 12 and opening/closing mechanism 15 can be detected.

The terminating circuit 8 is made of, for example, a resistor 8a, and serves to close the line 7 and to flow a weak current to the line 7 that does not activate the fire alarm detection circuit 22.

Next, the main body removal detection operation of the above embodiment will be explained.

First, when all the sensors 10 bodies 3 connected to the line 7 are fitted into the sockets 2, one side of the line 7 is sequentially relay-connected via the contact mechanism 12 of each sensor 1. Therefore, the current from the power supply 30 of the receiver 6 flows into the termination circuit 8.
The signal flows through the line 7 via.

Therefore, the line cutoff detection circuit 25 does not operate.

On the other hand, when the main body 3 of one of the sensors 1 is removed from the socket 2, the contact mechanism 12 is temporarily brought into a non-conducting state by the opening/closing mechanism 15, so that the line 7 is temporarily cut off.

Therefore, the line cutoff detection circuit 25 is activated, and the alarm device 2
9 is activated.

After the main body 3 is completely removed, the contact mechanism 12
Since it becomes conductive again, there is no problem with the subsequent fire alarm at the sensor 1.

Next, FIG. 17 is a wiring diagram showing another embodiment of the alarm of the present invention.

Further, FIG. 18 is a circuit diagram showing a sensor used in the above embodiment.

In the alarm shown in FIG. 17, each sensor 1 is provided with a periodic conduction circuit 31, and the receiver 6 is provided with a periodic interruption detection circuit 35 for detecting periodic interruption of the line 70.

The periodic conduction circuit 31 includes, for example, the relay terminals 7a, ? of the socket 2, as shown in FIG. An opening/closing contact 32b is connected between the contact mechanism 9 and the contact mechanism 9, which becomes electrically conductive when the main body 3 is fitted.
, an oscillation circuit 33 that oscillates when the main body 3 is removed, and a switching circuit 34 that periodically energizes the relay 32 with the output of the oscillation circuit 33.

This periodic conduction circuit 31 is connected to the contact mechanism 9 when the main body 3 is fitted.
When the main body 3 is removed because it is short-circuited and does not operate, the oscillation circuit 33 operates and drives the switching circuit 34.
The coil 32a is energized periodically to periodically open and close the switching contact 32b.

As a result, the line 7 is periodically cut off.

The periodic interruption detection circuit 35 can be configured, for example, by adding a pulse detection circuit (not shown) to the line interruption detection circuit 25 shown in FIG. 16, and detects periodic interruption of the line 70. do.

In the alarm of this embodiment, the line 7 is not cut off at all when the main body is fitted, but is periodically cut off after the main body is removed, so by detecting this periodic cut-off, it can be distinguished from a break in the line 7 itself. Separately, removal of the main body 3 can be detected.

Further, since conduction occurs periodically, there is no problem with subsequent fire alarms from the sensor 1.

As explained above, the present invention provides each sensor with a means for temporarily or periodically interrupting the relay of the line when the main body of the sensor is removed; Alternatively, by providing a means for detecting periodic interruption, removal of the main body can be detected without interfering with the operation of other sensors, which is highly effective in disaster prevention.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a sensor used in a conventional alarm, Fig. 2 is a wiring diagram showing a conventional alarm, and Fig. 3 A and B are the holding fittings and elastic pieces of the conventional sensor. 4 is a wiring diagram showing an embodiment of the alarm device of the present invention, and FIGS. 5 to 7 are various types of contact mechanisms used in the above embodiment. 8 to 12 are side views showing various aspects of the opening/closing mechanism used in the above embodiment, and FIG. 13 is a top view of the sensor body showing the mounting position of the opening/closing mechanism. Fig. 14 is a side view showing the contact mechanism and opening/closing mechanism in the plug-in sensor, Fig. 15 is a circuit diagram showing another embodiment of the contact mechanism, and Fig. 16 is a receiver used in the alarm of the present invention. A circuit diagram showing the machine,
FIG. 17 is a wiring diagram showing another embodiment of the alarm of the present invention, and FIG. 18 is a circuit diagram showing a sensor used in this embodiment. 1...Sensor, 2...Socket, meter
...Main body, 4...Holding metal fittings, 5...
- Fitting metal fitting, 6...Receiver, 7...Line, 8...Terminal circuit, 9, 12...Contact mechanism, 10... ...Detection part, 11...Elastic piece, 13...Micro inch, 14...
... Reed switch, 15 ... Opening/closing mechanism, 1
6...Insulating member, 17...Protrusion, 1
8...Magnet, 22...Fire alarm detection circuit, 25...Line interruption detection circuit, 24.29.
...Alarm device, 30...Power supply, 31...
. . . Periodic conduction circuit, 35 . . . Periodic interruption detection circuit.

Claims (1)

[Claims] 1. A plurality of fire detectors are sequentially connected in parallel to a line leading to a receiver, and a termination circuit is provided at the end of the line to form a closed circuit, and one of the lines is connected to In a fire alarm system in which each fire detector is sequentially connected to other fire detectors via relay, the line relay is cut off temporarily when the detector body is removed or periodically after removal. A fire alarm system characterized in that the receiver is provided with means for detecting temporary or periodic interruption of the line. 2. The fire alarm according to item 1 above, wherein each fire detector is provided with a contact mechanism that is always in a conductive state, and is also provided with an opening/closing mechanism that temporarily brings the contact mechanism into a non-conductive state when the detector main body is removed. . 3 Each fire detector is equipped with a periodic conduction circuit that activates when the detector main body is removed, in parallel with a contact mechanism that conducts when the main body is fitted, to periodically cut off the relay of the line after the main body is removed, and to connect the receiver to the , the fire alarm system according to the above item 1, further comprising a periodic interruption detection circuit for detecting periodic interruption of the line relay.